Thank you for posting but I actually believe that it is for GT Legends. I clicked on "mod" and read "Very important - You need a copy of GT Legends in order to install this mod" but further down they mentioned GTR2.

Edit:

Choice of Platform

We believe that our mods will mainly appeal to those who already have the sim they are based on - GT Legends. However, the team's primary focus for its mods is GTR2 as this offers the options of weather and custom championships, as well as improvements in other areas such as on-line and fps. But it is planned to release versions of the mods for GT Legends at some point after the GTR2 version is out. You will need a GT Legends disk to install the mod in GTR2.